Edwaed murphy



(No Model.)

B. MURPHY.

TENSION DEVICE FOR SEWING MACHINES. No. 324,579.

M MAWW lTE STATES EDWARD MURPHY,

on NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 324,579, dated August18, 1885.

Application filed September 24, 1884. (No model.) I

To call whom it may concern.-

Be it known that l, EDWARD MURPHY, of

the city, county, and State of New York, have invented a new and usefulImprovement in Tension Devices for Sewing-Machines; and I do herebydeclare that the following is a full and exact description thereof,reference being had to the accompanying drawings, and to the letters ofreference marked thereon, making a part of this specification.

This invention relates to that class of tension devices forsewing-machines in which the clamping-disks are placed upon thegooseneck of the machine in position to be actuated by a spring fittedupon the under side of the goose-neck and operated by the oscillation ofthe needle-arm.

In practical use it becomes necessary to provide for a nice adjustmentof the movement of the spring, in order to time the tension of the disksupon the thread and their release in exact accord with the drawing up ofthe thread into the cloth; and the object of my present invention is toobtain this nicety of adjustment in connection with a tension device ofthe class above named, and more par ticularly with the device describedin the Letters Patent granted. to me December 18, 1883, No. 290,345.

It consists in the combination, with the curved spring actuating thetension-disks, of an oscillating lever pivoted upon the pivotal studupon which the needle'arm vibrates, to move independently of said arm,the inner end or arm of the lever being made,as it rises,- to lift thefree end of the spring. This lever is coupled at its outer end by aconnectingrod with an eccentric secured on the main shaft of themachine, and which admits of adjustment thereon in the customary manner.

In the accompanying drawings, Figure l is an elevation of asewing-machine with the tension-disks and the pivotal stud of the needlearm in section, the needlearm being removed and its position illustratedby dotted lines. Fig. 2 is transverse section in line as a: of Fig. 1,the needle arm being broken at its lowest bend.

A is the cloth-plate; B, the main shaft; 0, the goose-neck or fixed armof the frame; D,

;the head; E, (in dotted lines,) the needle arm; F, the'spool stand, andG Gthe tensiondisks of the machine.

The tension-disks G G are arranged upon the upper side of the fixed arm0 in substan- Patent No. 290.345, of 1883, the lower disk being fittedin a recess in the upper side of the fixed arm of the frame, while theupper disk is made to rest upon the lower disk, and is adapted to beborne down thereon by the tension of a curved spring, H, fitted upon theunder side of the fixed arm 0, and connected to a cap-plate, J, restingupon the upper disk by means of a rod, K, passing through a centralaperture in the disks and in the arm 0. One end of the spring H issecured to the arm 0 at a point intermediate the rod K and the head D bymeans of a rivet or screw, L, and its free end extends nearly to thepivotal axis S of the needle-arm E.

Instead of extending the curved spring or spring-plate H to a pointopposite the pivotal axis of the needle-arm, the spring may be shortenedand a rigid arm or strip, M, be attached to its free end to extend tothe pivotal axis, as illustrated in Fig. 1 of the drawings.

Upon the stud-pin S, which constitutes the pivot of the needle-arm E,and between said arm and the bearing for the stud in the frame 0, alever, N, is pivoted, so that its inner shorter arm shall oscillateunder the end of the spring or spring-plate M, to come into contacttherewith at the end of its upward stroke and thereby lift the bar andspring. The outer end of this lever N is bent to pass around to the rearof the frame 0, and is coupled by means of a connecting-rod, P, to aneccentric, R, on the main shaft. This eccentric is adjustable on theshaft, and when properly adjusted is fixed by means of a setscrew, '1,in the customary manner. By means of this adjustment thethrow of theoscillating lever N may be regulated so as to cause it to lift thespring H at any desired moment in the movement of the needle-arm, sothat the tension of the spring upon the disks G G, and consequentlytheir clamping action on the thread, may be automatically set free atthe moment the stitch has been properly formed tially the mannerdescribed in my Letters and drawn up in the cloth, Without regard to R,upon the main shaft, substantially in the the thickness or character ofthe fabric. manner and for the purpose herein set forth. I claim as myinvention- In testimony whereof I have signed my name The combination,with the spring H, fitted to this specification in thepresence oftwosub- 5 under the fixed arm 0 of a sewing-machine, I scribing witnesses.

and adapted to actuate a tension disk or disks, G, supported upon saidarm, of a lever, N, DDxVARD MURPHY pivoted upon the pivotal stud of theneedle- Witnesses: arm E of the machine, and connected by a G. H.SPENCER, IO coupling-bar, P, with an adjustable eccentric, J. F. AOKER,Jr.

